Vehicle doors must be lockable from both the interior and the exterior of the vehicle, in order to safeguard the vehicle and its contents. In earlier vehicles, doors have conventionally been made manually lockable and unlockable from the interior of the vehicle, using a high-profile knob provided on the interior door panel sill.
Although older manually actuated mechanisms are well known, the associated door lock knobs, as traditionally employed, are provided having a high profile relative to the door panel sill to promote easy manipulation by the occupant. Unfortunately, such interior door lock knobs are also easily manipulated from the vehicle exterior, and are thus susceptible to unauthorized access, which may lead to theft of the vehicle and/or its contents.
More recently, in an effort to improve convenience and to discourage theft, electronic, or power, door locking systems have become quite popular. Power door locking systems are usually accessed from the interior using a simple door-mounted switch. Many power systems today also use a remote control key fob module, usable to remotely lock or unlock the vehicle.
These electronic systems can actuate the locking assemblies for all vehicle doors simultaneously, and are widely used because of their ease of use and convenience. In addition, they have the practical benefit of deterring theft, since the associated control switches are not easily manually manipulated from the exterior of the vehicle, using traditional theft tools such as wires inserted past the window glass.
However, when the only way of actuating a vehicle's locking mechanism is electronically controlled, there is a risk that an occupant could become trapped within the vehicle, in a situation when there is a failure of the electronic door locking system. Such a failure can occur due to a dead battery, vehicle damage resulting from an accident, or simple electronic malfunction.
A manually actuatable mechanism which is accessible from the vehicle interior is needed, to allow an occupant to access the door lock mechanism in situations when the electronic door switch is not functioning. Ideally, such a manually operable switch would incorporate anti-theft features, to resist unauthorized access using common theft devices.